Bucket mounting for trench hoe

ABSTRACT

A trench hoe which, when in operation, maintains the digging bucket at a given digging angle. The digging bucket is constructed as a ditcher and the dimension of the trapezoid control system consisting of the bucket, the dipper arm, the front thrust piston drive, and the link means between the front thrust piston drive and the dipper arm, in relation to the dimensions of the outrigger arm is such that the dipper arm in operation at the desired angle of slope or gradient is guided approximately parallel within a predetermined range of angles of slope or gradients.

United States Patent Schwing [is] 3,656,640 [451 Apr. 18, 1972 [72]Inventor:

[54] BUCKET MOUNTING FOR TRENCH HOE Friedrich Schwing, Rathausstr. 126,Wanne-Eickel, Germany [22] Filed: Nov. 12, 1970 [21] Appl.No.: 88,664

Related U.S. Application Data [62] Division of Ser. No. 817,062, Apr.17, 1969, Pat. No.

[52] U.S. Cl. ..2l4/l38 R, 214/770 [51] Int. Cl. ..E02f 3/32 [58] FieldofSearch ..2l4/138, l38 B, 138 C, DIG. 10,

[56] References Cited UNITED STATES PATENTS 3,487,958 1/1970 Shooketal.ugimssx 3,412,880 11/1968 Tweedale ..2l4/138 3,197,049 7/1965 Schwing..2l4/l38 Primary Examiner-Gerald M. Forlenza Assistant Examiner-JeroldM. Forsberg Attorney-Malcolm W. Fraser 7 [57] ABSTRACT A trench hoewhich, when in operation, maintains the digging bucket'at a givendigging angle. The digging bucket is constructed as a ditcher and thedimension of the trapezoid control system consisting of the bucket, thedipper arm, the front thrust piston drive, and the link means betweenthe front thrust piston drive and the dipper arm, in relation to thedimensions of the outrigger arm is such that the dipper arm in operationat the desired angle of slope or gradient is guided approximatelyparallel within a predetermined range of angles of slope or gradients.

3 Claims, 6 Drawing Figures PATENTEDAPR 18 m2 SHEET 1 BF 6 INVENTORFRIEDRICH SCHWING Pmimmm 18 m2 sum 2 OF 6 INVENTOR FRIEDRICH SCHWINGATTORNEY PATENTEDAPR 18 m2 SHFET 3 OF 6 ATTORNEY INVENTOR FRIEDRICHSCHWING ATTORNEY PATENTEDAPR 18 m2 sum 5 BF 6 ?ATENTEDAPR 18 m2 SHEET 5UF 6 INVENTOR FRIEDRIClSigHWING I WM AU. m.

ATTORNEY 1 BUCKET MOUNTING FOR TRENCII IIOE CROSS REFERENCE TO RELATEDAPPLICATION This application constitutes a division of my copendingapplication, Ser. No. 817,062, filed Apr. 17, 1969, and entitled BucketMounting For Trench I-Ioe, now US. Pat. No. 3586182.

BACKGROUND OF THE INVENTION The invention relates to a trench hoeprovided with a digging bucket which. is pivoted to a shaft foractuation by a forward thrust hydraulic piston. The bucket shaft may bepivoted to an outrigger arm, which is actuated by a rear thrust piston.A third thrust piston is provided foractuating the assembly.Suchmechanism must be as simple as possible to keep the cost as lowaspossible, but it must be controllable by the operator with a minimumof control movements;

With known trench hoes, the front piston drive, which serves for theactuation of the digging bucket, is pivoted to the shaft. With thesedevices, the excavator operator must actuate three thrust piston drivessimultaneously, if the digging bucket is guided along a straight lineand the correct digging angle is to be carried out. Therefore, thetrench produced in this manner is very inaccurate.

Trench hoes are, however, already known which entirely take awayfrom theoperator this type of complicated control movements. These trench hoesadhere exactly to a given digging angle, because the digging bucket isguided forcefully on a straight line. The technical expenditure requiredfor the purpose, however, is appreciable, because of the multiplicity ofnecessary control devices.

The trench hoe above described was previously solely to be driven with aloading or charging shovel, and insures, however, an almost parallelguidance of the shovel solely upon horizontal thrust at the height ofthe plane of position of the machine.

SUMMARY OF THE INVENTION The problem serving as basis for the inventionis to construct the trench hoe in such manner, that with a movementimparted to it, the digging bucket maintains a given digging angle. Thisproblem is solved according to the invention, in

that the digging bucket is constructed as a ditcher and that thedimension of the trapezoid control system is so chosen that the dipperarm in operation at a desired angle of slope or gradient is guidedapproximately parallel within a predetermined range of angles of slopeor gradients.

Thereby it is attained that upon control of the excavator operator, thefront thrust piston drive need not be adjusted at all or only to aslight degree for the maintenance of the angle of intersection. It maybe restricted substantially to the actuation entirely of the rear thrustpiston drive and of making corrections by the third thrust piston drive.

It is first of all surprising that if the excavator operator omits thesecorrections, a trial line results because apparently the parallelguidance characteristics of the ditcher are so excellent that throughraising of the excavator as the case may be, the correction omitted bythe excavator operator will be carried out automatically.

In accordance with the invention, the end of the front thrust pistondrive facing away fromthe digging bucket is connected with a controlsystem, which has a front control articulated to the dipper arm and arear control which is rotatably fixed to the outrigger arm.

This control system so dimensioned that the parallel controlcharacteristics of the trencher are maintained. 0n the other hand,however, by correspondingly dimensioning the lengths of the controls,the the guide drive and the dipper arm to the outrigger arm are from oneanother, that they can be accommodated without construction problems.

According to the invention, the front guide rod of the control system isarticulated between its two ends to the'dipper arm, whereby one of itsends is rotatably fixed to the front thrust piston drive and the otherend to the second guide rod swingably positioned on the outrigger arm.The front guide rod forms accordingly a double armed lever and theentire control system consists solely of two guide rods.

This holds true also for a further embodiment of the inven tion, inwhich the front thrust piston drive is articulated in the apex of thetwo control drive, whose ends are fixed rotatably to the dipper arm orto the outrigger arm, respectively.

In both forrns of embodiment ofthe invention, there results anadditional advantage that the length of the dipper ann may appreciablyexceed the length of the front thrust piston drive, because with thedescribed control system, the difference in length may be equalized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a trenchhoe showing the digging bucket in two positions, whereby the diggingplane extends horizontally and lies below the plane of the trench hoechassis; f

FIG. 2 is a side elevation of the trench hoe corresponding to FIG. 1,whereby the angle of slope or gradient increases slantingly from theplane of the trench hoe chassis;

FIG. 3 is a side elevation of the trench hoe corresponding to FIGS. 1and 2, the modus operandi with an angle of slope or gradient decreasingfrom the plane of the trench hoe chassis; and

FIGS. 4 to 6 are side elevations of a trench hoe corresponding to FIGS.1 to 3, but showing an alternate form of articulated connections betweenthe chassis and the digging bucket.

DESCRIPTION OF PREFERRED EMBODIMENTS In the figures, similar referencecharacters designate parts corresponding to one another.

The trench hoe has a chassis l, which is connected with the upperstructure -2 through a rotary connection 3 and stands on a plane ofposition 4.

The digging device mounted on the excavator is first to be explained inits basic traits;

It consists of a digging implement constructed as bucket 5, which isswingable on the end of a bent dipper arm 6 about an axis of rotation 7with the aid of a front hydraulic thrust piston drive 8, which consistsof a cylinder 9 and a piston rod 10. The piston rod 10 is pivoted to theapex of a triangular shift lever 11, one arm of which is pivoted to theinner end of the bucket 5 and the other arm of which is pivoted to thedipper arm 6 near the pivotal connection 7. The front part 13 of aground outrigger arm 14 carries a shaft 15 for the pivoting of thedipper arm 6. For swinging-the dipper arm 6 about the axis 15 is a rearthrust piston drive 16, whose piston rod 17 is pivoted at 18 to therearward end of the dipper arm 6, while a cylinder 19 is pivoted at 20to the outrigger arm 14.

The rearward part 21 of the outrigger arm 14 is pivoted at 22 to theupper structure of the trench hoe. The outrigger arm I4 is actuated by athird thrust piston drive 23.

The digging bucket 5, the dipper arm 6, the front thrust piston drive 8and the partial length of the outrigger arm 14 between the dipper armaxis 15 and the pivot 12 of the front thrust piston drive 8 form atrapezoid control system (Trapezlenkersystem). This trapezoid controlsystem is laid out in relation to the dimensions of the outrigger arm 14so that the dipper arm 6 is guided approximately parallel at desiredangles of slope or gradients, three of which are shown which all liewithin a predetermined range of angles of slope or gradient. Insofar,the showings in the figures are indicated accurately enough and thedotted line showings indicate that insignificant deviations from thepredetermined angles of starting movement are adjusted at the end of thedigging movement. These are, however, for practical conditionsnegligibly small and could furthermore be equalized by means of acorresponding control movement.

Deviating from the embodiments shown by way of example, the rear thrustpiston drive 16 may also be so disposed that it does not engage on theprojecting end of a dipper arrn but at a desired point between the axis15 and the axis 7. The articulation of the front thrust piston drive 8has solely as prerequisite that it is conducted outside of the axis ofrotation 15, so that the axis 12 may be disposed at a desired pointbetween the axis 15 and the axis 22 of the ground outrigger arm.

If the trench hoe in accordance with the invention is laid out so thatin the large range of angles of slope or gradients necessary fortrenches a sufficient parallel guidance of the digging bucket isattained, then also other digging implements which do not have to beguided parallel in so great an angle range, may be utilized effectively,for example, loading shovel and highdigger or shovel.

As shown in FIGS. 1 to 3, the free end of the cylinder 9 of the frontthrust piston drive 8 is pivoted to a guide drive 30 at 12. This controlsystem consists of a front control lever 31 and a rear guide link 32.The front guide is shown in the embodiment according to FIGS. 1 to 3 asa double-armed lever, which is pivoted between its two ends at 33 to adipper arm 6. One of the two ends carries the pivot 12 for the frontthrust piston drive 8, while the other end has the pivot 34 for thefront end of the rear guide link 32. The other end of the guide link 32is pivoted at 36 to the front part 13 of the outrigger arm 14.

In contrast to the embodiment by way of example illustrated in FIGS. 1to 3, in the embodiment by way of example accord ing to FIGS. 4 to 6,the front guide 31 is constructed as a one arm lever link, and thecontrol drive has an apex 37, to which both the free end of the cylinder9 of the front thrust piston drive 8 as well as the front end of therear guide link 32 are pivoted. The other end of the rear guide link 32likewise forming a one arm lever is pivoted at 36 again to the outriggerarm 14.

In all figures it is shown in two phases, that the digging bucket uponexploration is guided approximately parallel under a designated anddesired angle of slope or gradient within a predetermined range ofangles of slope or gradients. The parallel guidance is attained by meansof a corresponding dimensioning of the control system of the diggingbucket 5, dipper arm 6, front thrust piston drive 8 and the partiallength of the outrigger arm or jib 14 between dipper arm axis andpivoting of the front thrust pistron drive, in which the describedcontrol system 30 is interpolated, in relation to the dimensions of theoutrigger arm 14.

In practice it has been found that the trench hoe operator does not needto readjust except in a very small degree for the maintenance of theparticular digging angle. He may thereupon limit himself essentially tofull actuation of the rear thrust piston drive 16 and with correcting atthe time the third thrust piston drive 23. If he omits thesecorrections, the straight line of-diggingoccurs by itself, becauseapparently the guidance characteristics of the bucket 5 guided inparallel are so excellent that the bucket rises in case the operatoromits the corrections in proper time and thereby insures automaticallythe maintenance of the digging angle.

What I claim is:

l. A trench hoe comprising a digging bucket, a triangular shift leverhaving one arm pivoted to the inner end of said bucket, a fronthydraulic thrust piston drive having a piston rod pivoted to the apex ofsaid shift lever, a dipper arm at one side of said shift lever andpivoted at its outer end to said bucket inner end and in spaced relationto the pivotal connection of said shift lever and said bucket, a pivotalconnection between the other arm of said shift lever and said dipper armin close spaced relation to said pivotal connection between said dipperarm and bucket, an outrigger arm, link means providing an articulatedconnection between the inner end of said front thrust piston drive andsaid dipper arm and said outrigger arm, a pivotal connection betweensaid dipper arm and said outrigger arm and disposed at the other side ofthe dipper arm facing away from said triangular shift lever, the endportion of said dipper arm extending beyond said last pivotalconnection, a rear hydraulic thrust piston drive connected to the end ofsaid last end portion and dis osed above said outrigger arm, thearrangement being such hat a trapezoid control linkage for said diggingbucket is provided consisting of said bucket, said dipper arm, saidfront thrust piston drive, and said link means between said front pistondrive and said dipper arm, and said control linkage being so dimensionedin relation to the dimensions of said outrigger arm that said diggingbucket is guided in operation approximately parallel under a desiredangle of slope or gradient within a predetennined range of angles ofslope or gradient.

2. A trench hoe as claimed in claim 1, in which said link meansproviding an articulated connection comprises a front control leverpivoted at one end to the inner end of said front thrust piston driveand at an intermediate portion to said dipper arm, and a guide linkpivotally connected at one end to the other end of said front controllever and at the opposite end to said outrigger arm.

3. A trench hoe as claimed in claim 1, in which said link meansproviding an articulated connection comprises a pair of link anns, eachbeing pivoted at one end to the inner end of said front thrust pistondrive, means pivotally connecting the opposite end of one link arm tothe adjacent portion of said dipper arm, and means pivotally connectingthe opposite end of the other link arm to the end of said outrigger armadjacent the pivotal connection between said dipper arm and saidoutrigger arm.

1. A trench hoe comprising a digging bucket, a triangular shift leverhaving one arm pivoted to the inner end of said bucket, a fronthydraulic thrust piston drive having a piston rod pivoted to the apex ofsaid shift lever, a dipper arm at one side of said shift lever andpivoted at its outer end to said bucket inner end and in spaced relationto the pivotal connection of said shift lever and said bucket, a pivotalconnection between the other arm of said shift lever and said dipper armin close spaced relation to said pivotal connection between said dipperarm and bucket, an outrigger arm, link means providing an articulatedconnection between the inner end of said front thrust piston drive andsaid dipper arm and said outrigger arm, a pivotal connection betweensaid dipper arm and said outrigger arm and disposed at the other side ofthe dipper arm facing away from said triangular shift lever, the endportion of said dipper arm extending beyond said last pivotalconnection, a rear hydraulic thrust piston drive connected to the end ofsaid last end portion and disposed above said outrigger arm, thearrangement being such that a trapezoid control linkage for said diggingbucket is provided consisting of said bucket, said dipper arm, saidfront thrust piston drive, and said link means between said front pistondrive and said dipper arm, and said control linkage being so dimensionedin relation to the dimensions of said outrigger arm that said diggingbucket is guided in operation approximately parallel under a desiredangle of slope or gradient within a predetermined range of angles ofslope or gradient.
 2. A trench hoe as claimed in claim 1, in which saidlink means providing an articulated connection comprises a front controllever pivoted at one end to the inner end of said front thrust pistondrive and at an intermediate portion to said dipper arm, and a guidelink pivotally connected at one end to the other end of said frontcontrol lever and at the opposite end to said outrigger arm.
 3. A trenchhoe as claimed in claim 1, in which said link means providing anarticulated connection comprises a pair of link arms, each being pivotedat one end to the inner end of said front thrust piston drive, meanspivotally connecting the opposite end of one link arm to the adjacentportion of said dipper arm, and means pivotally connecting the oppositeend of the other link arm to the end of said outrigger arm adjacent thepivotal connection between said dipper arm and said outrigger arm.